diff --git a/scsh/syscalls.scm b/scsh/syscalls.scm
index b0a0558..54ad5f3 100644
--- a/scsh/syscalls.scm
+++ b/scsh/syscalls.scm
@@ -313,8 +313,8 @@
 (define-errno-syscall (set-file-group thing gid)
   (lambda (thing gid)
     (generic-file-op thing
-		     (lambda (fd)    (set-fdes-uid&gid/errno fd    gid -1))
-		     (lambda (fname) (set-file-uid&gid/errno fname gid -1)))))
+		     (lambda (fd)    (set-fdes-uid&gid/errno fd    -1 gid))
+		     (lambda (fname) (set-file-uid&gid/errno fname -1 gid)))))
 
 
 ;;; Uses real uid and gid, not effective. I don't use this anywhere.